Apparatus and method for providing access to a buried pipe

ABSTRACT

The pipe access device is comprised of a curved plate adapted to engage an underground pipe along an arc of the outer surface of the pipe, and a boss extending upwardly from the curved plate about an aperture in the curved plate. The curved plate extends along an arc of the outer surface of the curved plate that corresponds to a central angle of the pipe less than or equal to 180°. The curved plate includes a concave surface with a radius of curvature less than a radius of curvature of the outer surface of the pipe so as to bias the curved plate against the outer surface of the pipe when the curved plate is flexed to engage the pipe. The pipe access device is for use in providing access to the buried pipe that requires minimal excavation and disruption of the soil.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. Ser. No.12/540,104 filed Aug. 12, 2009, now U.S. Pat. No. 8,172,482 issued onMay 8, 2012, both of which are hereby incorporated by reference in theirentirety.

BACKGROUND OF THE INVENTION

The present invention relates to an apparatus and method for providingaccess to a buried pipe, such as a sewer pipe and the like.

Conventional sewer lines include a main pipe which extends along thestreet in a direction parallel to the street. Each house has a lateralpipeline that extends from the home and connects to the main pipeline.

It is often desirable to provide a clean-out to the lateral pipeadjacent the main sewer pipe. Many lateral pipes have been buriedwithout such a clean-out. In order to provide a clean-out, it isnecessary to make a wide and extensive excavation so that persons canenter the excavation and attach a clean-out pipe to the lateral pipe.This results in considerable disruption to the soil and the yard aroundthe house.

U.S. Pat. No. 6,705,801 to Kiest discloses a saddle and method of usingthe same for providing access to buried pipe lines which creates aminimum of disruption of the soil. The preferred embodiment disclosed inthe patent includes a curved plate that when positioned on the outersurface of the sewer pipe extends beyond the spring line of the pipe. Byattaching the saddle to the pipe, a downward force is applied that, inturn, causes the curved plate to spread radially outwardly and then snapback into place to secure the saddle to the outer surface of the pipe.In the preferred embodiment disclosed, the curved plate extends along anarc of the outer surface of the pipe corresponding to a central angle ofthe pipe more than 180°. The reference also discloses that curved platespanning an angle of less than 180° may also be used.

However, as the curved plate spans an arc corresponding to a centralangle of the pipe less than or equal to 180°, there is no snappingaction as described above, as the curved plate does not extend beyondthe spring line of the pipe. In addition, if the edges of the curvedplate flex outwardly and are held in this position, the boss extendingupwardly from the curved plate tends to oblong in shape. This isproblematic when attempting to mount a circular extension pipe withinthe boss and maintaining a fluid tight seal therebetween.

Problems therefore remain when using a saddle having a curved plate thatspans an angle of 180° or less around the outer surface of the pipe.

Therefore, a primary object, feature and/or advantage of the presentinvention is the provision of an improved method for providing access toa buried pipe.

A further object, feature and/or advantage of the present invention is anew apparatus and method for providing access to a buried pipe using asaddle having a curved plate that spans an arc corresponding to an arcangle of 180° or less that can be effectively secured to a substantiallycircular pipe.

A still further object, feature and/or advantage of the presentinvention is a new method and apparatus for providing access to a buriedpipe using a saddle with a curved plate as described above that does notresult in an oval-shaped boss extending upwardly from the curved platewhen the curved plate is in a flexed position on the outer surface ofthe pipe.

These and/or other objects, features and/or advantages of the presentinvention will become apparent with reference to the remainder of thespecification and claims.

BRIEF SUMMARY OF THE INVENTION

One aspect of the present invention includes an apparatus for providingaccess to an interior bore of a pipe located below a surface of theground. The apparatus, referred to as a pipe access device, includes acurved plate adapted to engage the pipe along an arc of the outersurface of the pipe, the arc defining a corresponding central angle ofthe pipe less than or equal to 180°. The apparatus also includes a bossextending upwardly from the curved plate about an aperture in the curvedplate. The curved plate includes a concave surface having a radius ofcurvature less than the radius of curvature of the outer surface of thepipe so that the curved plate is biased against the outer surface of thepipe when the curved plate is expanded or flexed to engage the pipe.Because the curved plate initially has a radius of curvature less thanthe radius of curvature of the outer surface of the pipe, when thecurved plate is flexed and pushed down on top of the pipe, the curvedplate provides a pinching or clamping action around the outer surface ofthe pipe.

In a preferred form, the pipe is a lateral sewer pipe, and the apparatusfurther includes an extension pipe that extends upwardly from the bossnear the surface of the ground. An adhesive material can also bedisposed between the curved plate and the outer surface of the pipe toassist in holding the curved plate on the pipe.

Another aspect of the invention includes an apparatus as described abovewherein the boss has an oval-shaped cross-section that changes to asubstantially circular cross-section when the curve plate is expanded orflexed to engage the pipe. Thus, once the pipe access device is securedto the pipe, a substantially circular extension pipe can easilytelescope inside the boss.

Another aspect of the present invention includes a method of providingaccess to an interior bore of a pipe buried beneath the surface of theground. The method generally includes excavating the ground to expose aportion of the pipe, taking a pipe access device as describedpreviously, attaching the pipe access device to the pipe, cutting anaccess hole in the pipe aligned with a boss bore formed by the boss ofthe pipe access device, and mounting an extension pipe to the boss toprovide fluid communication with the surface of the ground. The pipeaccess device is attached to the pipe by pressing the curved platedownwardly onto the pipe so that the curved plate is biased against theouter surface of the pipe when the curve plate is expanded to engage thepipe. It is preferred that the boss initially have an oval-shapedcross-section that changes to a substantially circular cross-sectionwhen the curved plate is expanded or flexed to fit over the pipe.

The present invention contemplates providing access to all kinds ofpipelines, including, but not limited to mainline sewer pipelines,lateral sewer pipelines, gas pipelines, and potable water pipelines.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing a buried lateral and main sewer pipeand a pipe access device for providing access to the interior of thelateral sewer pipe.

FIG. 2 is a perspective partially exploded view of the device shown inFIG. 1.

FIG. 3 is a sectional view taken along line 3-3 of FIG. 1.

FIG. 4 is an exploded view similar to FIG. 3.

FIG. 5 is a top view of the pipe access device showing the oval-shape ofthe boss before expansion to engage the sewer pipe.

FIG. 6 is a top view of the pipe access device showing the circularshape of the boss after expansion of the curved plate to engage thesewer pipe.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

For exemplary purposes only, the present invention is described indetail with reference to providing access to a lateral sewer pipe 10.The present invention is equally applicable to both main and lateralsewer pipes 10, 16 as well as other types of buried pipe.

Referring to FIG. 1, a lateral sewer pipe 10 connected to a main sewerpipe 16 is buried beneath the ground 12 having an upper surface 14. Anaperture 18 is cut in the lateral pipe 10 and provides access to aninterior bore 26 of the pipe 10. Generally this is the last operationperformed in providing access to the sewer pipe 10. The sewer pipe 10includes an inner surface 20 and an outer surface 22 that extend alongan arc corresponding to a central angle of 360°.

An excavated hole 24 is dug in the ground 12 from its upper surface 14to a depth that exposes the sewer pipe 10. The hole 24 has a diameter D₃that provides access from the sewer pipe 10 up to the upper surface 14of the ground 12, while minimizing disruption to the ground.

As best shown in FIGS. 1-3, a pipe access device 28 includes a curvedplate or saddle 30 and a boss 32. The boss 32 has a boss bore 34extending there through. Boss bore 34 has a lower end 33 communicatingwith the sewer bore 26 through the aperture 18 and extending upwardly toan upper end 35. The curved plate 30 has a flange 31 at its outer tips,and extends along an arc associated with a central angle of less than180°.

Although the pipe 10 is discussed in the context of having a circularshape, it is to be understood that the pipe 10 need only have asubstantially circular cross-section and not necessarily a perfectlycircular cross-section. The curved plate 30 having a concave surface 39is operably connected to the outer surface 22 of the pipe 10 along anarc of the outer surface of the pipe. That arc defines a correspondingcentral angle of the pipe 10 that is less than or equal to 180°. Putanother way, the concave surface 39 of the curved plate 30 spans an arclength of the outer surface 22 of the pipe 10 that is less than half ofthe circumference of the outer surface of the pipe. The concave surface39 in its initial state has a radius of curvature less than a radius ofcurvature of the outer surface 22 of the pipe 10. As such, the curvedplate 30 is biased against the outer surface of the pipe 10 when thecurved plate 30 it is expanded or flexed to engage the pipe 10, as shownin FIG. 3. When the access pipe 28 is secured to the pipe 10, the curvedplate 30 is flexed such that the concave surface 39 follows a radius ofcurvature substantially equal to the radius or curvature of the outersurface 22 of the pipe 10.

An extension pipe 36 has an extension pipe bore 37 extending therethrough. The extension pipe 36 has a first end 38 telescoped withrespect to upper end 35 of boss bore 34. The first end 38 rests on anannular flange 41 protruding inwardly from the boss bore 34 atapproximately a tangent to sewer pipe 10, although it could be higher orlower.

As illustrated in FIG. 3, a fluid resistant seal 42 is made between thecurved plate 30 and the sewer pipe 10 by an adhesive 48. This fluidresistant seal 42 provides a fluid tight seal between the curved plate30 and the outer surface 22 of sewer pipe 10. The radius R₁ of curvature44 of the curved plate 30 is somewhat less than the radius of curvatureR₂ of the outer surface 22 of the sewer pipe 10 (see FIG. 4). Inaddition, the longitudinal centerline 54 (FIG. 3) or spring line of thesewer pipe 10 is below the flanges 31 of the curved plate 30. Thematerial of curved plate 30 is flexible and resilient so that it can beexpanded to the radius of curvature R₂ of the outer surface 22 of thesewer pipe 10 when the curved plate is expanded or flexed to cover thepipe 10. Forming the curved plate 30 and 32 from PVC is suitable for thepresent invention.

Referring to FIGS. 5 and 6, the shape of the boss 32 changes from anoval-shape 50 to a substantially circular shape 52 when the curved plate30 expands in the direction of arrows 68 to engage sewer plate 10. Theoval-shape 50 is somewhat exaggerated for illustration purposes. As thecurved plate 30 expands from FIG. 5 to FIG. 6, the boss deforms toproduce the circle 52. This is important to allow the insertion of theextension pipe 36 into the upper end 35 of boss bore 34 and provide afluid tight seal therebetween. This change in the shape of the boss 32from an oval-shape 50 to a circular shape 52 is reflected by a majordiameter D₁ and a minor diameter D₂ of the ovular shape 50 changing to adiameter D of a circle 52.

A flexible sleeve 56 (FIGS. 3 and 4) is provided outside of the firstend 38 of extension pipe 36 and the upper end 35 of boss bore 34. Thesleeve 56 includes two bands 58,60 which surround and engage theflexible sleeve 56 and are secured by screws 62,64 to create a fluidtype seal. While the flexible sleeve 56 is shown, the pipe could beattached by an adhesive or other material conventionally used byplumbers in connecting plastic pipe together.

In operation, the excavated hole 24 is dug down to the sewer pipe 10buried beneath the surface of the ground 14. This can all be done aboveground remotely from the location of the sewer pipe 10 and does notrequire the installer to enter the excavated hole 24. The preferredmethod is to use a vacuum excavator manufactured by Vactor Manufacturingunder the trade name VACTOR®, at the address of 1721 South IllinoisStreet, Streator, Ill. 61364. This device excavates a hole and removesthe soil from the hole with a minimum of disturbance of the soil. Thediameter D3 of the hole need be only large enough to permit theinsertion of the curved plate 30 into the hole, and need be only deepenough to expose a portion of the outer surface of sewer pipe 10.

An assembly 70 includes the extension pipe 36, the saddle or curvedplate 30 and the boss bore 34. The assembly 70 also includes theflexible sleeve 56, adhesive or other material. Before curved plate 30engages the sewer pipe 10, the adhesive 66 is applied so that a fluidtype seal 42 is provided by adhesive 66 between curved plate 30 and theouter surface 22 of sewer pipe 10. The sealing material may be anuncured plastic resin or it can be a physical sealing means such asgaskets or double side tape. All this is assembled above the excavatedhole 24 before lowering within the excavated hole 24. Once the assemblyis lowered into the excavated hole 24, the operator pushes on theextension pipe 36 to cause the curved plate 30 to expand and to surroundthe outer surface 22 of the sewer pipe 10 less than 180°. At this timethe fluid tight seal is provided between the telescoped upper end 35 ofthe boss bore 34 and the first end 38 of the extension pipe 36.

Next an aperture 26 is cut within the sewer pipe 10. The preferredmachine for making the aperture is a cutting machine manufactured byMilwaukee Tools under the trade name Diamond Coring Bits, sold in theGrainger Catalog at the address of 2701 Downers Grove, Ill. 60515.

In the drawings and specification there has been set forth a preferredembodiment of the invention, and although specific terms are employed,these are used in a generic and descriptive sense only and not forpurposes of limitation. Changes in the form and the proportion of partsas well as in the substitution of equivalents are contemplated ascircumstance may suggest or render expedient without departing from thespirit or scope of the invention as further defined in the followingclaims.

What is claimed is:
 1. An apparatus for providing access to an interiorbore of a pipe located below a surface of the ground, the pipe having anouter surface and a substantially circular cross section, the apparatuscomprising: a curved plate adapted to engage the outer surface of thepipe, the curved plate having outer tips spanning less than or equal tohalf the circumference of the pipe and including an interior surfacebiased against the pipe adjacent an aperture in said pipe; and a bossextending from an aperture in the curved plate and away from the pipe;wherein the boss and aperture having an oval-shaped cross section thatchange to a substantially circular cross section when the curved plateis expanded to engage the pipe.
 2. The apparatus of claim 1 wherein thecurved plate comprises an arc, the length of the arc being less than thelength of arc corresponding to 180° of the pipe surface.
 3. Theapparatus of claim 1 wherein the curved plate has a radius of curvatureless than the radius of curvature of the pipe to bias the plate againstthe pipe.
 4. The apparatus of claim 1 further comprising flangesextending from the outer tips of the curved plate away from the pipe. 5.The apparatus of claim 1 further comprising an annular flange positionedabout the interior of the boss and extending toward the axis of theboss.
 6. The apparatus of claim 1 further comprising an extension pipeextending away from the boss to near the surface of the ground.
 7. Theapparatus of claim 6 wherein the extension pipe is telescopicallymounted to the boss.
 8. The apparatus of claim 6 further comprising aflexible sleeve positioned at least partially about a portion of theboss and extension pipe.
 9. The apparatus of claim 8 further comprisingat least one band positioned at least partially about the flexiblesleeve.
 10. The apparatus of claim 1 further comprising an adhesivematerial disposed between the surface of the curved plate and the outersurface of the pipe.
 11. A method of providing access to an interiorbore of a pipe buried beneath a surface of the ground, the pipe havingan outer surface and a substantially circular cross section, the methodcomprising: excavating the ground to expose a portion of the pipe;taking an assembly comprising a curved plate adapted to engage the outersurface of the pipe, a boss extending from an aperture in the curvedplate and away from the pipe, and an extension pipe extending away fromthe curved plate; wherein the boss having an oval-shaped cross sectionthat changes to a substantially circular cross section when the curvedplate is expanded to attach the pipe access device to the sewer pipe;attaching the assembly to the pipe by biasing the curved plate about theouter surface of the pipe; wherein the assembly is biased to the pipe bythe curved plate having a radius less than the radius of the pipe andthe curved plate expands to attach to the pipe; and making an accesshole in the pipe aligned with an aperture of the bore and the apertureof the curved plate.
 12. The method of claim 11 wherein the excavatingstep is performed using vacuum excavation.
 13. The method of claim 11further comprising: applying an uncured and hardenable sealing materialto the concave surface of the curved plate before attaching the pipeaccess device to the pipe; and allowing the sealing material to cure andharden after attaching the pipe access device to the pipe.
 14. Themethod of claim 11 wherein the curved plate of the assembly covers lessthan 180° of the pipe when the assembly has been attached to the pipe.15. The method of claim 14 further comprising positioning a flexiblesleeve over a portion of the boss and extension pipe before attachingthe assembly to the pipe.
 16. An assembly for providing access to aninterior bore of a pipe located below a surface of the ground, the pipehaving an outer surface and a substantially circular cross section, theassembly comprising: a device comprising a curved plate having a radiusof curvature less than the radius of curvature of the pipe and an arccorresponding to less than half of the circumference of the pipe, and aboss extending from the curved plate about an aperture in the plate, theboss comprising a cylinder with an aperture equal to the curved plateaperture; wherein the boss and aperture having an oval-shaped crosssection that change to a substantially circular cross section when thecurved plate is expanded to engage the pipe; and an extension pipeextending from the boss away from the curved plate.
 17. The assembly ofclaim 16 wherein the boss further includes an annular flange about theinterior of the boss, wherein the extension pipe is positioned adjacentthe annular flange.
 18. The assembly of claim 16 further comprising anadhesive material applied to a concave surface of the curved plate. 19.An apparatus for providing access to an interior bore of a pipe locatedbelow a surface of the ground, the pipe having an outer surface and asubstantially circular cross section, the apparatus comprising: a curvedplate adapted to engage the outer surface of the pipe, the curved platehaving outer tips spanning less than or equal to half the circumferenceof the pipe and including an interior surface positioned adjacent thepipe adjacent an aperture in said pipe and held in place without the useof straps; and a boss extending from an aperture in the curved plate andaway from the pipe; wherein the boss having an oval-shaped cross sectionthat changes to a substantially circular cross section when the curvedplate is expanded to attach the apparatus to the pipe.
 20. A method ofproviding access to an interior bore of a pipe buried beneath a surfaceof the ground, the pipe having an outer surface and a substantiallycircular cross section, the method comprising: excavating the ground toexpose a portion of the pipe; taking an assembly comprising a curvedplate adapted to engage the outer surface of the pipe, an adhesiveapplied to an interior surface of the curved plate, a boss extendingfrom an aperture in the curved plate and away from the pipe, and anextension pipe extending away from the curved plate; wherein the bosshaving an oval-shaped cross section that changes to a substantiallycircular cross section when the curved plate is expanded to attach thepipe access device to the sewer pipe; attaching the assembly to the pipeby connecting the curved plate about the outer surface of the pipe withthe adhesive disposed between the pipe and the curved plate; and makingan access hole in the pipe aligned with an aperture of the bore and theaperture of the curved plate.